Founding Member

Don't have them but I saw those after I had purchased my 620's. If I'd seen those first, I would definitely have bought them instead. I wanted the stiffness for handling, but it isn't very practical for ALL driving. I would love a smoother ride over these crappy roads, railroad tracks, potholes,etc...

I am using the big block 600's in mine. the ride is alittle stiff a lower speeds but the handling is great. at higher speeds it smooths out on the ride and doesnot give you that boat in the water floating bounce.

Founding Member

In my 69, with 351w I'm running the
67/73 SMALL AND INTERMEDIATE BLOCK, 390 TO 520 lbs/in

I LIKE EM!

I've got the TCP subs and x-brace, 1 1/8" sway bar with all polygraphite bushings from PST, and the 17" wheels - and it goes through turns sooo nicely.. I haven't done any hard turns over 40 because the back tires start to rub. If your car is mostly street, I don't think you can go wrong. I compensated by getting the bigger sway bar - this way going straight I can get a little more cushion, and when I get into the turns, I figure I'll let the sway bar do its job.

Founding Member

Originally posted by corpse In my 69, with 351w I'm running the
67/73 SMALL AND INTERMEDIATE BLOCK, 390 TO 520 lbs/in

I LIKE EM!

I've got the TCP subs and x-brace, 1 1/8" sway bar with all polygraphite bushings from PST, and the 17" wheels - and it goes through turns sooo nicely.. I haven't done any hard turns over 40 because the back tires start to rub. If your car is mostly street, I don't think you can go wrong. I compensated by getting the bigger sway bar - this way going straight I can get a little more cushion, and when I get into the turns, I figure I'll let the sway bar do its job.

Click to expand...

Totally agree... get the 390-520lb ones...they call them small and intermediate block springs for a reason

Founding Member

I know I started this thread last May, but am hoping more people have install the progressive rated springs since.
I plan on running these with GW uppers and not TCP now. If you have any new feedback please post. Also would like to know which rear springs you are running and how you like your setup.
Thank you.Josh

Click to expand...

Yes. I have since installed them. I'm very pleased.
TCP uppers/lowers/strut rods.
Rear is 5 leaf. They are fine. I ripped the spring perches from the rear axle
a few months ago when I ran ET Streets, and have since re-welded and gusseted them. The 5 leafs held up just fine.